Biography Walter De Maria

Walter De Maria, a reclusive American sculptor whose multifaceted achievement and sly Dadaist humor helped give rise to earthworks, Conceptual Art and Minimal art, on an often monumental scale, died on Thursday in Los Angeles. He was 77 and lived in New York.

Mr. De Maria went to California two months ago to celebrate his mother's 100th birthday and had a stroke there a few days later. He had remained there for treatment. Elizabeth Childress, the director of his studio, said that he died in his sleep, perhaps of a second stroke.